1. Field of the Invention
The present invention relates to a robot teaching method for changing an operation program for a robot, and more specifically, to a method of teaching a robot by which the teaching points of an operation program can be simply changed.
2. Description of the Related Art
Robots have been widely used in welding lines and assembly lines for automobiles. In these manufacturing lines for automobiles, even if an operation program for a robot is created, each automobile is not always stopped at a given position. To cope with this problem, a position of an object is confirmed by using a visual sensor or the like and the operation program is corrected, based on data obtained therefrom, so that each object can be accurately processed.
More specifically, positions of the operation program for the robot are taught by using a master body. Next, a visual sensor recognizes the position of the master body and stores it as a reference position. Next, an actual workpiece body is placed in position, the visual sensor recognizes the position of the workpiece body, notifies a robot control unit of an amount of dislocation between the master body and the workpiece body as correction data, and the robot control unit adds the correction data to the operation program in order to correctly process the workpiece body.
Nevertheless, a problem arises in that when teaching positions and the like of an operation program are changed, a master body must again be placed in position to change the operation program. This job of placing the master body is time consuming. Further, the master body must be kept in the vicinity of a manufacturing line at all times.
Conversely, since the tool center point (TCP) of the robot moves on a locus corrected by the correction data on the workpiece body, it is actually difficult to change the operation program by using only the workpiece body.